Organic compound having acenaphtho[1,2-k]benzo[e]acephenanthrene derivative, light-emitting device, and image display apparatus

ABSTRACT

Provided is an acenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented by general formula (1): 
                         
wherein R 1  to R 16  are each independently selected from a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group; and at least one of R 1  to R 8  and R 10  to R 15  is selected from a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heterocyclic group.

TECHNICAL FIELD

The present invention relates to a novel organic compound. The presentinvention also relates to an organic light-emitting device and imagedisplay apparatus that include the organic compound.

BACKGROUND ART

Organic light-emitting devices include an anode, cathode, and a thinfilm containing a fluorescent organic compound and disposed between theanode and the cathode. Excitons of the fluorescent organic compound aregenerated by injecting electrons and holes from the electrodes, and theorganic light-emitting devices utilize light emitted when the excitonsare returned to the ground state. Such organic light-emitting devicesare also referred to as “organic electroluminescent devices” or “organicEL devices”.

Recently, organic light-emitting devices have become markedly advancedand the possibility of a wide variety of applications has been suggestedtherefor because of the high luminance achieved by a low appliedvoltage, a variety of emission wavelengths, a high-speed responsiveness,and the possibility of realization of a thin, lightweight light-emittingdevices. Heretofore, novel compounds have been actively developed. Thisis because creation of novel compounds is important to providehigh-performance organic light-emitting devices. For example, PatentLiteratures 1 to 3 describe examples of organic compounds used as thematerials for a light-emitting layer.

However, from the standpoint of practical application, there is still aroom for improvement in the organic compounds described in PatentLiteratures 1 to 3 and organic light-emitting devices including thesame. Specifically, for practical application, an optical output withhigher luminance and higher conversion efficiency are necessary.Furthermore, improvements are necessary in terms of durability, forexample, a change with time due to long-term use and degradation due toan atmospheric gas containing oxygen, moisture, or the like.

Furthermore, considering an application to a full-color display or thelike, a blue-light emission having good color purity and high luminousefficiency is necessary. However, technologies related to these issueshave not yet satisfactorily been developed. Accordingly, in particular,an organic light-emitting device having high color purity, high luminousefficiency, and high durability and a material that realizes such anorganic light-emitting device have been desired.

CITATION LIST Patent Literature

-   PTL 1 Japanese Patent Laid-Open No. 2-247278-   PTL 2 Japanese Patent Laid-Open No. 8-113576-   PTL 3 Japanese Patent Laid-Open No. 11-12205

SUMMARY OF INVENTION

The present invention has been made to solve the above-describedproblems in the related art. More specifically, the present inventionprovides a novel organic compound that is suitably used mainly in ablue-light-emitting device and an organic light-emitting deviceincluding the same.

Solution to Problem

The present invention provides anacenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented bygeneral formula (1) below.

In general formula (1), R₁ to R₁₆ are each independently selected from ahydrogen atom, a halogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group. In addition, atleast one of R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group.

An organic light-emitting device including the novel compound of thepresent invention can realize a light emission with high efficiency andhigh luminance.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view showing organic light-emitting devicesaccording to the present invention and units configured to supply theorganic light-emitting devices according to the present invention withelectrical signals.

FIG. 2 is a schematic view showing a pixel circuit connected to a pixeland a signal line and current supply line that are connected to thepixel circuit.

FIG. 3 is a diagram showing the pixel circuit.

FIG. 4 is a schematic cross-sectional view showing organiclight-emitting devices and TFTs disposed under the organiclight-emitting devices.

DESCRIPTION OF EMBODIMENTS

Compounds of the present invention will now be described in detail. Anorganic compound according to the present invention is anacenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented bygeneral formula (1).

In general formula (1), R₁ to R₁₆ are each independently selected from ahydrogen atom, a halogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group. In addition, atleast one of R₁ to R₈ and R₁₀ to R₁₆ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group.

In general formula (1), examples of the alkyl group in the substitutedor unsubstituted alkyl group include, but are not limited to, a methylgroup, an ethyl group, a n-propyl group, an isopropyl group, a n-butylgroup, a tert-butyl group, a sec-butyl group, an octyl group, a1-adamantyl group, and a 2-adamantyl group.

In general formula (1), examples of the alkoxy group in the substitutedor unsubstituted alkoxy group include, but are not limited to, a methoxygroup, an ethoxy group, a propoxy group, a 2-ethyl-octyloxy group, aphenoxy group, a 4-tert-butylphenoxy group, a benzyloxy group, and athienyloxy group.

In general formula (1), examples of the amino group in the substitutedor unsubstituted amino group include, but are not limited to, anN-methylamino group, an N-ethylamino group, an N,N-dimethylamino group,an N,N-diethylamino group, an N-methyl-N-ethylamino group, anN-benzylamino group, an N-methyl-N-benzylamino group, anN,N-dibenzylamino group, an anilino group, an N,N-diphenylamino group,an N,N-dinaphthylamino group, an N,N-difluorenylamino group, anN-phenyl-N-tolylamino group, an N,N-ditolylamino group, anN-methyl-N-phenylamino group, an N,N-dianisolylamino group, anN-mesityl-N-phenylamino group, an N,N-dimesitylamino group, anN-phenyl-N-(4-tert-butylphenyl)amino group, and anN-phenyl-N-(4-trifluoromethylphenyl)amino group.

In general formula (1), examples of the aryl group in the substituted orunsubstituted aryl group include, but are not limited to, a phenylgroup, a naphthyl group, an indenyl group, a biphenyl group, a terphenylgroup, and a fluorenyl group.

In general formula (1), examples of the heterocyclic group in thesubstituted or unsubstituted heterocyclic group include, but are notlimited to, a pyridyl group, an oxazolyl group, an oxadiazolyl group, athiazolyl group, a thiadiazolyl group, a carbazolyl group, an acridinylgroup, and a phenanthrolyl group.

In general formula (1), examples of the substituent that may be includedin the substituents R₁ to R₁₆, namely, the alkyl, alkoxy, amino, aryl,and heterocyclic groups include, but are not limited to, alkyl groupssuch as a methyl group, an ethyl group, and a propyl group; aralkylgroups such as a benzyl group; aryl groups such as a phenyl group and abiphenyl group; heterocyclic groups such as a pyridyl group and apyrrolyl group; amino groups such as a dimethylamino group, adiethylamino group, a dibenzylamino group, a diphenylamino group, and aditolylamino group; alkoxyl groups such as a methoxyl group, an ethoxylgroup, a propoxyl group, and a phenoxyl group; a cyano group; andhalogen atoms such as fluorine, chlorine, bromine, and iodine.

Specific examples of the compound represented by general formula (1) areshown below. However, the present invention is not limited thereto.

The novel organic compounds according to the present invention will nowbe described in more detail.

In general, in order to increase the luminous efficiency of organiclight-emitting devices, it is desirable that a luminescence centermaterial have a high emission quantum yield. In order to achieve this,it is necessary to satisfy the following conditions:

(1) The oscillator strength is high.

(2) An oscillating portion of the skeleton related to light emission issmall.

As for a physical property required for a material suitable forblue-light emission in organic EL displays, it is important for aluminescent material to have an emission peak in the range of 430 to 480nm. The organic compounds according to the present invention can emitlight having an emission peak in the range of 430 to 480 nm.

As for (1) above, it is important to increase the symmetry of themolecular skeleton related to the light emission. However, under aforbidden transition condition specific to highly symmetric molecules,light emission does not occur in some cases. Alternatively, by furtherextending conjugation with a direction in which the conjugate plane isthe longest as an axis, the dipole moment of the molecule is increasedto increase the oscillator strength. In this respect, the organiccompounds according to the present invention have a fused-ring structurein which conjugation is extended from the 8-position to the 11-positionof benzo[k]fluoranthene. This structure further increases the moment ofbenzo[k]fluoranthene. As a result, the organic compounds according tothe present invention have structures with high oscillator strengths.

As for (2) above, when the skeleton related to the light emission doesnot have a rotational structure, a decrease in the quantum yield due torotational oscillation can be suppressed.

Furthermore, the basic skeleton of the organic compounds according tothe present invention, i.e., theacenaphtho[1,2-k]benzo[e]acephenanthrene skeleton itself has a maximumemission wavelength in the blue region. Furthermore, since this basicskeleton does not have a rotational structure, a decrease in the quantumyield due to rotational oscillation can be suppressed. A descriptionwill be made using benzo[k]fluoranthene as an example of a comparativebasic skeleton. Comparing 7,12-diphenylbenzo[k]fluoranthene, which isobtained by substituting each of the 7-position and the 12-position ofbenzo[k]fluoranthene with a phenyl group, to9,16-diphenylacenaphtho[1,2-k]benzo[e]acephenanthrene of the presentinvention, which is obtained by substituting each of the 9-position andthe 16-position of acenaphtho[1,2-k]benzo[e]acephenanthrene with aphenyl group, the former compound has a maximum emission wavelength of428 nm, whereas the compound of the present invention has a maximumemission wavelength of 440 nm.

7,12-Diphenylbenzo[k]fluoranthene

9,16-Diphenylacenaphtho[1,2-k]benzo[e]acephenanthrene

Accordingly, even the basic skeleton of the compounds of the presentinvention alone has an emission wavelength suitable for blue-lightemission, and in addition, a high quantum yield is achieved.Furthermore, since the organic compounds according to the presentinvention each have two five-membered ring structures in the skeletonthereof, they have low energy levels of the HOMO and LUMO. Compoundshaving a lower oxidation potential require larger energy to be oxidized.That is, the organic compounds according to the present invention arestable against oxidation. When the organic compounds according to thepresent invention are used as luminescent materials, the compounds aresuitable as electron-trapping luminescent materials.

Furthermore, according to the organic compounds of the presentinvention, in order to adjust the wavelength to be suitable for adesired device, a method of adjusting the wavelength by introducing asubstituent may be employed. As for substituents suitable for shiftingthe wavelength to the long-wavelength side, the substituents arepreferably introduced into the 1-position to the 8-position and the10-position to the 15-position because substituents at the 9-positionand the 16-position do not significantly change the wavelength.Absorption values (S1) of the acenaphtho[1,2-k]benzo[e]acephenanthreneskeleton and substituted acenaphtho[1,2-k]benzo[e]acephenanthrenederivatives each having an aryl group at different bonding positionswere calculated. A change in the maximum emission wavelength can beestimated by the absorption values. As for the calculation method, aquantum chemical calculation at the B3LYP/6-31G* level was performedusing the density function theory. Table 1 shows the results.

TABLE 1 Structural formula Absorption value (S1) Unsubstituted

411.5 nm Substituted with phenyl at 5-position

422.1 nm Substituted with phenyl at 9-position

413.4 nm Substituted with phenyl at 12-position

419.5 nm Substituted with phenyl at 15-position

420.1 nm Substituted with phenyl at 16-position

411.7 nm

Although all positions of substitution were not calculated, at the9-position and the 16-position, the absorption value was increased by0.5 to 1.9 nm as compared with that of the unsubstituted compound, andthus the wavelength is hardly shifted to the long-wavelength side. Incontrast, at the other positions, the absorption value was increased by8.0 to 10.6 nm, as compared with that of the unsubstituted compound.Accordingly, in order to shift the wavelength to the long-wavelengthside in the wavelength control, substituents at the 1-position to the8-position and the 10-position to the 15-position are preferable.According to the present invention, by introducing substituents into the1-position to the 8-position and the 10-position to the 15-position, theemission wavelength can be shifted to the long-wavelength side toprepare luminescent materials suitable for blue, or green to red. Inaddition, the organic compounds according to the present invention havehigh planarity. Therefore, when the organic compounds are unsubstituted,excimers are readily formed by intermolecular stacking. Accordingly, inview of suppression of the formation of excimers, an aryl group ispreferably introduced to each of the 9-position and the 16-position.

A1 to A164 are compounds each constituted by only carbon atoms andhydrogen atoms. That is, these compounds do not contain a heteroatomsuch as nitrogen. Furthermore, each of the 9-position and the16-position of A1 to A164 is substituted with an aryl group.Specifically, this aryl group is a phenyl group or other aryl groupconstituted by only carbon atoms and hydrogen atoms (hereinafterreferred to as “hydrocarbon”). Since these positions are substitutedwith the aryl groups, these compounds have steric hindrance.Furthermore, at least one of the 1-position to the 8-position and the10-position to the 15-position of A1 to A164 is substituted with an arylgroup. Specifically, this aryl group is also a phenyl group or otheraryl group constituted by only carbon atoms and hydrogen atoms. Since atleast one of these positions is substituted with such an aryl group, theemission wavelength of the molecule is made longer than the emissionwavelength of the basic skeleton. The aryl group bonded to each of the9-position and the 16-position and the aryl group bonded to at least oneof the 1-position to the 8-position and the 10-position to the15-position may be the same or different.

Conjugation of the basic skeleton is extended by introducing an arylgroup into at least one of these positions. As a result, since theband-gap of the molecule is narrowed, the substituted compound can emitlight having a wavelength longer than the emission wavelength of thebasic skeleton itself, which is an unsubstituted compound. In addition,since the 9-position and the 16-position are orthogonal to the basicskeleton, molecules having substituents at these positions have athree-dimensional structure. As a result, stacking of the molecules canbe suppressed to suppress concentration quenching. Accordingly, tuningof the emission wavelength can be achieved by introducing substituentsinto the 1-position to the 8-position and the 10-position to the15-position. Furthermore, formation of an excimer can be suppressed byintroducing substituents into the 9-position and the 16-position. Inaddition, all the substituents of the organic compounds are constitutedby hydrocarbons. Accordingly, when the half of the total of theoxidation potential and the reduction potential of the basic skeleton isassumed to be a center position, the potential width ofoxidation-reduction of these organic compounds can be changed whilemaintaining the center position.

In the organic compounds according to the present invention, when asubstituent is a hydrocarbon in which an alkyl group is directly bonded,e.g., the substituent shown in any of B1 to B37, the alkyl group isdirectly bonded to the basic skeleton. As a result, the compound issubjected to the donating property of the substituent, the centerposition is shifted from the oxidation-reduction potential, and theoxidation potential tends to be high.

Furthermore, according to the organic compounds of the presentinvention, since a substituent having an sp³ hybrid orbital is directlybonded to the basic skeleton, stacking of the molecules can besuppressed. Thus, the formation of excimer can be effectivelysuppressed. In addition, the formation of excimer can be furthersuppressed by introducing, as an additional substituent, a substituenthaving a fused-ring structure into an end of an alkyl group which is asubstituent introduced into the basic skeleton.

In addition, when the organic compound has, as a substituent, aheteroatom-containing substituent such as a heterostructure-containingaryl group or amino group, as shown in C1 to C33, it is possible tocontrol a change in the oxidation-reduction potential due to theheterostructure. As a result, not only the maximum emission wavelengthcan be shifted to the long-wavelength side and the organic compounds canbe used as an electron-trapping luminescent material, but also theorganic compounds can be used in applications such as an electrontransport material, a hole transport material, and a hole-trappingluminescent material.

It was found that, in this respect,acenaphtho[1,2-k]benzo[e]acephenanthrene derivatives which are organiccompounds according to the present invention can achieve a high quantumyield that can be used in the blue region.

As described above, according to the organic light-emitting device ofthe present invention, at least oneacenaphtho[1,2-k]benzo[e]acephenanthrene derivative compound iscontained in a layer composed of an organic compound. Theacenaphtho[1,2-k]benzo[e]acephenanthrene derivative compounds of thepresent invention can be used as a luminescent material for ablue-light-emitting device. However, the applications of the compoundsare not limited thereto. Specifically, the compounds of the presentinvention may be used as a luminescent material, a host material, atransport material, and the like for a green-light-emitting device.

Organic compounds represented by general formula (1) can be synthesizedby synthetic route 1 described below. Although this synthesis methodproduces isomers depending on the position of a substituent R, there isno significant difference in the luminescence properties so long as theisomers have the same R. Accordingly, a desired compound may be isolatedby recrystallization or the like and used or the isomers may be used inthe form of a mixture. The mixture ratio is not particularly limitedbecause the luminescence properties of the mixture are not significantlydecreased compared with those of a single compound. When the compoundsare used as a mixture, crystallinity is suppressed and thus an advantagesuch as suppression of concentration quenching can also be expected. Asfor other substituents, the synthesis can be conducted by substitutinghydrogen atoms with other substituents such as an alkyl group, a halogenatom, a phenyl group, and the like.

Synthetic Route 1

Various organic compounds according to the present invention can besynthesized from starting materials D1 to D4. Organic compounds that canbe synthesized are shown in the table below (synthetic compounds inTable 2 below). Table 2 also shows the starting materials.

TABLE 2 D1 D2 D3 D4 Syn- thesis ex- ample  1

Syn- thesis ex- ample  2

Syn- thesis ex- ample  3

Syn- thesis ex- ample  4

Syn- thesis ex- ample  5

Syn- thesis ex- ample  6

Syn- thesis ex- ample  7

Syn- thesis ex- ample  8

Syn- thesis ex- ample  9

Syn- thesis ex- ample 10

Syn- thesis ex- ample 11

Syn- thesis ex- ample 12

Syn- thesis ex- ample 13

Syn- thesis ex- ample 14

Syn- thesis ex- ample 15

Syn- thesis ex- ample 16

Syn- thesis ex- ample 17

Syn- thesis ex- ample 18

— Syn- thesis ex- ample 19

— Syn- thesis ex- ample 20

Syn- thesis ex- ample 21

Syn- thesis ex- ample 22

— Syn- thesis ex- ample 23

Syn- thesis ex- ample 24

Syn- thesis ex- ample 25

— Syn- thesis ex- ample 26

— Syn- thesis ex- ample 27

Syn- thesis ex- ample 28

Syn- thesis ex- ample 29

Syn- thesis ex- ample 30

Syn- thesis ex- ample 31

— Syn- thesis ex- ample 32

Synthetic compounds Synthesis example  1

Synthesis example  2

Synthesis example  3

Synthesis example  4

Synthesis example  5

Synthesis example  6

Synthesis example  7

Synthesis example  8

Synthesis example  9

Synthesis example 10

Synthesis example 11

Synthesis example 12

Synthesis example 13

Synthesis example 14

Synthesis example 15

Synthesis example 16

Synthesis example 17

Synthesis example 18

Synthesis example 19

Synthesis example 20

Synthesis example 21

Synthesis example 22

Synthesis example 23

Synthesis example 24

Synthesis example 25

Synthesis example 26

Synthesis example 27

Synthesis example 28

Synthesis example 29

Synthesis example 30

Synthesis example 31

Synthesis example 32

Next, an organic light-emitting device according to the presentinvention will be described. The organic light-emitting device accordingto the present invention includes at least a pair of electrodes, i.e.,an anode and a cathode, and an organic compound layer interposed betweenthe electrodes. This organic compound layer contains the organiccompound represented by general formula (1) above. Organiclight-emitting devices are devices in which a luminescent material,which is an organic compound, disposed between a pair of electrodesemits light. When one layer constituting the organic compound layer is alight-emitting layer, the light-emitting layer may be composed of theorganic compound according to the present invention alone or may bepartly composed of the organic compound according to the presentinvention. The phrase “light-emitting layer may be partly composed ofthe organic compound according to the present invention” means that theorganic compound according to the present invention may be a maincomponent of the light-emitting layer or an auxiliary component thereof.Herein, among all compounds constituting the light-emitting layer, themain component refers to a compound contained in a large amount in termsof weight or the number of moles, for example, and the auxiliarycomponent refers to a compound contained in a small amount. A materialused as the main component can also be referred to as “host material”. Amaterial used as the auxiliary component can also be referred to as“dopant (guest) material”, “luminescence assist material” or “chargeinjection material”.

When the organic compound according to the present invention is used asthe guest material, the concentration of the guest material to the hostmaterial is preferably 0.01% by weight or more and 20% by weight orless, and more preferably, 0.5% by weight or more and 10% by weight orless. The wavelength of the light emitted from the light-emitting layercan be made longer than the wavelength of the solution by 5 nm or moreand 20 nm or less by varying the concentration of the guest material inany one of these two ranges.

When the light-emitting layer is composed of a host material and guestmaterial having a carrier transport property, a main process that leadsto light emission includes the following steps.

1. Transportation of electrons and holes inside the light-emittinglayer.

2. Generation of excitons of the host material.

3. Transmission of excitation energy among molecules of the hostmaterial.

4. Transfer of the excitation energy from the host material to the guestmaterial.

A desired energy transfer and light emission in each of the steps occurin competition with various deactivation steps.

Naturally, in order to increase the luminous efficiency of the organiclight-emitting device, the emission quantum yield of a luminescencecenter material (e.g., guest material) itself must be high. However, howthe energy transfer between the molecules of the host material orbetween the molecules of the host material and the guest material isefficiently performed is also an important factor. The cause ofluminescence degradation due to electrical conduction has not yet becomeclear. However, it is believed that such degradation relates to at leastthe luminescence center material itself or the environmental changesthat are brought to the luminescence center material by the nearbymolecules.

Under these circumstances, the inventors of the present inventionconducted various investigations and found that when a compoundrepresented by general formula (1) of the present invention describedabove is used as the host material or the guest material of alight-emitting layer, in particular, as the guest material thereof, thedevice outputs light with a high efficiency and high luminance and hasmarkedly high durability.

Next, an organic light-emitting device of the present invention will bedescribed in detail. The organic light-emitting device of the presentinvention includes at least a pair of electrodes, i.e., an anode and acathode, and an organic compound layer interposed between theelectrodes. In the organic light-emitting device, the organic compoundlayer contains at least one organic compound represented by generalformula (1).

At least one compound layer other than the organic compound layer may beprovided between the pair of electrodes. Two or more compound layersincluding the organic compound layer may be provided between the pair ofelectrodes. In such a case, the device having such a structure isreferred to as “multilayer organic light-emitting device”.

A first example to a fifth example of multilayer organic light-emittingdevices will be described below.

The first example of the multilayer organic light-emitting device has astructure in which an anode, a light-emitting layer, and a cathode aresequentially provided on a substrate. The organic light-emitting deviceof this example is useful when a material having a hole transportproperty, an electron transport property, and a light-emitting propertyby itself is used in the light-emitting layer, or when compounds havingrespective properties are mixed and used in the light-emitting layer.

The second example of the multilayer organic light-emitting device has astructure in which an anode, a hole-transporting layer, anelectron-transporting layer, and a cathode are sequentially provided ona substrate. The organic light-emitting device of this example is usefulwhen a material having a hole transport property and a material havingan electron transport property are used in the corresponding layers orwhen a material having both these properties is used in both thehole-transporting layer and the electron-transporting layer, and aluminescent substance is used in combination with a simple holetransport substance or electron transport substance that has nolight-emitting property. In such a case, the light-emitting layer iseither the hole-transporting layer or the electron-transporting layer.

The third example of the multilayer organic light-emitting device has astructure in which an anode, a hole-transporting layer, a light-emittinglayer, an electron-transporting layer, and a cathode are sequentiallyprovided on a substrate. This is a device in which functions of carriertransportation and light emission are separated from each other. Acompound having a hole transport property, a compound having an electrontransport property, and a compound having a light-emitting property maybe adequately used in combination. Accordingly, the flexibility ofmaterial selection is significantly increased, and various compoundshaving different emission wavelengths can be used. Consequently, the hueof light emission can be diversified. Furthermore, carriers or excitonsare effectively confined in the center light-emitting layer to improvethe luminous efficiency.

The fourth example of the multilayer organic light-emitting device has astructure in which an anode, a hole injection layer, a hole-transportinglayer, a light-emitting layer, an electron-transporting layer, and acathode are sequentially provided on a substrate. The organiclight-emitting device of this example is advantageous in that theadhesiveness between the anode and the hole-transporting layer isimproved and a hole injection property is improved. Accordingly, thisstructure is effective for reducing the voltage.

The fifth example of the multilayer organic light-emitting device has astructure in which an anode, a hole injection layer, a hole-transportinglayer, a light-emitting layer, a hole/exciton-blocking layer, anelectron-transporting layer, and a cathode are sequentially provided ona substrate. In this structure, a layer (hole/exciton-blocking layer)that blocks holes or excitons from passing through the cathode side isinterposed between the light-emitting layer and theelectron-transporting layer. The luminous efficiency can be effectivelyimproved by using a compound having a significantly high ionizationpotential in the hole/exciton-blocking layer.

In the present invention, a light emission region containing thecompound represented by general formula (1) refers to a region of thelight-emitting layer described above. However, the first to fifthexamples of the multilayer organic light-emitting devices are merely thebasic device structures, and the structure of an organic light-emittingdevice including the organic compound according to the present inventionis not limited to the above examples. The organic light-emitting devicemay have various other layer structures. For example, an insulatinglayer may be provided between an electrode and an organic layer. Anadhesive layer or an interference layer may be provided. Alternatively,the electron-transporting layer or the hole-transporting layer may becomposed of two layers having different ionization potentials.

The compound represented by general formula (1) used in the presentinvention can be used in any one of the first example to the fifthexample described above. In the organic light-emitting device accordingto the present invention, at least one organic compound represented bygeneral formula (1) used in the present invention is contained in alayer containing an organic compound. In particular, the organiccompound represented by general formula (1) may be used as a guestmaterial in the light-emitting layer.

The organic compound according to the present invention may be used as ahost material in the light-emitting layer.

The organic compound according to the present invention may be used in alayer other than the light-emitting layer, namely, any one of a holeinjection layer, a hole-transporting layer, a hole/exciton-blockinglayer, an electron-transporting layer, and an electron injection layer.

In addition to the organic compound of the present invention, existinglow-molecular weight or high-molecular weight hole-transportingcompounds, luminescent compounds, electron-transporting compounds, andthe like may be used in combination as required.

Examples of such compounds will be described below. Holeinjection/transport materials may have a high hole mobility so thatholes can be easily injected from an anode and the injected holes can betransported to the light-emitting layer. Examples of the low-molecularweight and high-molecular weight materials having holeinjection/transport properties include, but are not limited to,triarylamine derivatives, phenylenediamine derivatives, stilbenederivatives, phthalocyanine derivatives, porphyrin derivatives,polyvinylcarbazole, polythiophene, and other electrically conductivepolymers.

Examples of host materials mainly include, but are not limited to, notonly the compounds shown in Table 3 and derivatives of the compoundsshown in Table 3, but also fused-ring compounds (such as fluorenederivatives, naphthalene derivatives, anthracene derivatives, pyrenederivatives, carbazole derivatives, quinoxaline derivatives, andquinoline derivatives), organoaluminum complexes such astris(8-quinolinolato)aluminum, organozinc complexes, triphenylaminederivatives, and polymer derivatives such as polyfluorene derivativesand polyphenylene derivatives.

TABLE 3 H1

H2

H3

H4

H5

H6

H7

H8

H9

H10

H11

H12

H13

H14

H15

H16

H17

H18

H19

H20

H21

H22

H23

H24

H25

H26

H27

H28

H29

H30

H31

H32

The electron injection/transport material can be adequately selectedfrom materials to which electrons are easily injected from a cathode andwhich can transport the injected electrons to the light-emitting layer.The material is selected in consideration of, for example, the balancewith the hole mobility of the hole injection/transport material.Examples of the materials having electron injection/transport propertiesinclude, but are not limited to, oxadiazole derivatives, oxazolederivatives, pyrazine derivatives, triazole derivatives, triazinederivatives, quinoline derivatives, quinoxaline derivatives,phenanthroline derivatives, and organoaluminum complexes.

The material for the anode may be a material having a work function ashigh as possible. Examples thereof include metal elements such as gold,platinum, silver, copper, nickel, palladium, cobalt, selenium, vanadium,and tungsten; alloys thereof; and metal oxides such as tin oxide, zincoxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide.Electrically conductive polymers such as polyaniline, polypyrrole, andpolythiophene can also be used. These electrode substances may be usedalone or in combinations of two or more substances. The anode may have asingle-layer structure or a multilayer structure.

On the other hand, the material for the cathode may be a material havinga low work function. Examples thereof include metal elements such asalkali metals, e.g., lithium; alkaline earth metals, e.g., calcium;aluminum; titanium; manganese; silver; lead; and chromium. Alloyscombining these metal elements can also be used. Examples thereofinclude magnesium-silver, aluminum-lithium, and aluminum-magnesium.Metal oxides such as indium tin oxide (ITO) can also be used. Theseelectrode substances may be used as alone or in combinations of two ormore substances. The cathode may have a single-layer structure or amultilayer structure.

Examples of the substrate used in the organic light-emitting device ofthe present invention include, but are not particularly limited to,opaque substrates such as a metal substrate and a ceramic substrate, andtransparent substrates such as a glass substrate, a quartz substrate,and a plastic sheet. The luminescent color can be controlled byproviding a color filter film, a fluorescent color conversion filterfilm, a dielectric reflecting film, or the like on the substrate.

A protective layer or a sealing layer may be provided on the prepareddevice in order to prevent the device contacting oxygen, moisture, andthe like. Examples of the protective layer include inorganic materialfilms such as a diamond thin film, metal oxide films, and metal nitridefilms; polymer films such as fluorocarbon resin films, a polyethylenefilm, silicone resin films, and a polystyrene resin film; andphotocurable resin films. The device may be covered with, for example,glass, a gas-impermeable film, or a metal and packaged with an adequatesealing resin.

In the organic light-emitting device of the present invention, a layercontaining the organic compound of the present invention and layerscomposed of other organic compounds are formed by the methods describedbelow. In general, a thin film is formed by a vacuum evaporation method,an ionized vapor deposition method, a sputtering method, a plasmadeposition method, or an existing coating method (for example, spincoating, dipping, a cast method, a Langmuir-Blodgett (LB) technique, oran ink jet method) that involves dissolving a compound in an adequatesolvent. Among these, when a layer is formed by a vacuum evaporationmethod, a solution coating method, or the like, crystallization does notreadily occur and thus the resulting layer has good stability with time.When a coating method is used to form a film, an adequate binder resinmay be used in combination with the compound.

Examples of the binder resin include, but are not limited to,polyvinylcarbazole resins, polycarbonate resins, polyester resins, ABSresins, acrylic resins, polyimide resins, phenolic resins, epoxy resins,silicone resins, and urea resins. These binder resins may be used aloneas a homopolymer or a copolymer or used as a mixture of two or moretypes of resin. Furthermore, existing additives such as a plasticizer,an antioxidant, or an ultraviolet absorber may be optionally used incombination.

The organic light-emitting device of the present invention can beapplied to products that require energy saving and high luminance.Application examples thereof include light sources of displayapparatuses, illuminating apparatuses, and printers, and backlights forliquid crystal display apparatuses.

When the organic light-emitting device is applied to a displayapparatus, a high-visibility, lightweight, flat panel display thatrealizes energy saving can be obtained. The display apparatus can beused as an image display apparatus such as a personal computer, atelevision, or an advertising medium. Alternatively, the displayapparatus may be used in a display unit of an image pickup apparatussuch as a digital still camera or a digital video camera. Alternatively,the display apparatus may be used in an operation display unit of anelectrophotographic image-forming apparatus, namely, a laser beamprinter, a copy machine, or the like.

Alternatively, the organic light-emitting device may be used as a lightsource that is used when a latent image is exposed on a photosensitivemember of an electrophotographic image-forming apparatus, namely, alaser beam printer, a copy machine, or the like. A plurality of organiclight-emitting devices that can be independently addressed may bearranged into an array (e.g., lines) and desired exposure may beperformed on a photosensitive drum to form a latent image. The use oforganic light-emitting devices of the present invention can decrease thespace that has been previously required for arranging a light source,polygon mirrors, and various optical lenses. When the organiclight-emitting device is applied to illuminating apparatuses and thebacklights, the effect of energy saving can be expected. The organiclight-emitting device of the present invention can also be used as asurface light source.

As described above, the luminescent color can be controlled by providinga color filter film, a fluorescent color conversion filter film, adielectric reflecting film, or the like on a substrate supporting theorganic light-emitting device of the present invention. A thin-filmtransistor (TFT) may be formed on the substrate and connected to theorganic light-emitting device to control the emission/non-emission.Alternatively, a plurality of organic light-emitting devices may bearranged in a matrix shape, that is, arranged in an in-plane directionand used as an illuminating apparatus.

Next, a display apparatus that uses the organic light-emitting device ofthe present invention will be described. This display apparatus includesthe organic light-emitting device of the present invention and a unitconfigured to supply electrical signals to the organic light-emittingdevice of the present invention.

The display apparatus of the present invention will now be describedwith reference to the accompanying drawings by taking an active matrixsystem as an example.

FIG. 1 is a schematic view of an example of the structure of a displayapparatus according to an embodiment. The display apparatus includesorganic light-emitting devices of the present invention and unitsconfigured to supply electrical signals to the organic light-emittingdevices of the present invention. FIG. 2 is a schematic view showing apixel circuit connected to a pixel, and a signal line and a currentsupply line that are connected to the pixel circuit.

The units configured to supply electrical signals to the organiclight-emitting devices of the present invention include a scanningsignal driver 11, an information signal driver 12, and a current supplysource 13 in FIG. 1 and a pixel circuit 15 in FIG. 2.

Referring to a display apparatus 1 shown in FIG. 1, the scanning signaldriver 11, the information signal driver 12, and the current supplysource 13 are arranged and connected to gate selection lines G,information signal lines I, and current supply lines C, respectively. Asshown in FIG. 2, pixel circuits 15 are arranged at intersections betweenthe gate selection lines G and the information signal lines I. One pixel14 constituted by the organic light-emitting device according to thepresent invention is provided for each corresponding pixel circuit 15.The pixel 14 is an organic light-emitting device. Accordingly, in thedrawing, organic light-emitting devices are illustrated as luminouspoints. In the drawing, an upper electrode of an organic light-emittingdevice may be formed as a common upper electrode for other organiclight-emitting devices. Alternatively, the upper electrodes of therespective organic light-emitting devices may be separately formed.

The scanning signal driver 11 sequentially selects the gate selectionlines G1, G2, G3, . . . and Gn. In synchronization with this, imagesignals are applied to the pixel circuits 15 from the information signaldriver 12 through one of the information signal lines I1, I2, I3, . . .and In.

Next, operation of the pixels will be described. FIG. 3 is a circuitdiagram showing a circuit constituting one pixel arranged in the displayapparatus shown in FIG. 1. In FIG. 3, a second thin-film transistor(TFT) 23 controls the current for causing an organic light-emittingdevice 24 to emit light. In a pixel circuit 2 shown in FIG. 3, when aselection signal is applied to the gate selection line Gi, a firstthin-film transistor 21 turns to the ON state, and an image signal Ii issupplied to a capacitor (C_(add)) 22 to determine a gate voltage of thesecond thin-film transistor 23. A current is supplied from the currentsupply line Ci to the organic light-emitting device 24 in accordancewith the gate voltage of the second thin-film transistor 23. The gatepotential of the second thin-film transistor 23 is retained in thecapacitor (C_(add)) 22 until the first thin-film transistor 21 isscanned and selected next time. Accordingly, the current continues to besupplied to the organic light-emitting device 24 until the next timescanning is performed. Thus, it is possible to constantly cause theorganic light-emitting device 24 to emit light during one frame period.

Although not shown in the drawings, the organic light-emitting deviceaccording to the present invention can also be used in a voltage-writedisplay apparatus in which a thin-film transistor controls the voltagebetween the electrodes of the organic light-emitting device 24.

FIG. 4 is a schematic view showing an example of the cross-sectionalstructure of a TFT substrate used in the display apparatus shown inFIG. 1. The structure will now be described in detail by taking aprocess of producing the TFT substrate as an example. In producing adisplay apparatus 3 shown in FIG. 4, first, a moisture-proof film 32 forprotecting components (TFTs and an organic layer) to be formed thereonis formed on a substrate 31 composed of glass or the like by coating.Silicon oxide, a composite material of silicon oxide and siliconnitride, or the like is used as the material for the moisture-proof film32. Next, a gate electrode 33 is formed by depositing a metal such aschromium (Cr) on the moisture-proof film 32 by sputtering, and thenpatterning the chromium film to have a predetermined circuit shape.

Subsequently, a gate insulating film 34 is formed by depositing siliconoxide or the like by a plasma chemical vapor deposition (CVD) method, acatalytic chemical vapor deposition (cat-CVD) method, or the like, andthen patterning the silicon oxide film. Next, a semiconductor layer 35is formed by depositing a silicon film by the plasma CVD method or thelike (and annealing the silicon film at a temperature of 290° C. orhigher if necessary), and patterning the silicon film in accordance witha circuit shape.

Furthermore, a drain electrode 36 and a source electrode 37 are formedon the semiconductor layer 35 to form a TFT device 38. Thus, a circuitas shown in FIG. 3 is formed. Next, an insulating film 39 is formed onthe TFT devices 38. Subsequently, a contact hole (through-hole) 310 isformed so that a metal anode 311 for an organic light-emitting device isconnected to the source electrode 37.

A multilayered or single-layered organic layer 312 and a cathode 313 aresequentially stacked on the anode 311. As a result, the displayapparatus 3 is obtained. In order to prevent degradation of the organiclight-emitting devices, a first protective layer 314 and a secondprotective layer 315 may also be provided. By driving the displayapparatus including the organic light-emitting devices of the presentinvention, high-quality images can be stably displayed for a long periodof time. Note that the switching device of the above display apparatusis not particularly limited. The display apparatus can be easily appliedto a single-crystal silicon substrate, an MIM device, an amorphous-Si(a-Si) device, or the like.

An organic light-emitting display panel can be obtained by sequentiallystacking a multilayer or single-layer organic light-emitting layer and acathode layer on the ITO electrode. By driving the display panel thatuses the organic compound of the present invention, high-quality imagescan be stably displayed for a long period of time.

As for a direction in which the light is output from the device, eitherone of the bottom emission configuration (configuration in which lightis output from the substrate side) or the top emission configuration(configuration in which light is output from the side opposite thesubstrate) may be used.

EXAMPLES

The present invention will be more specifically described by way ofExamples, but the present invention is not limited thereto.

Example 1 Synthesis of Exemplary Compounds A20 and A21

First, 10.5 g (48 mmol) of fluoranthene-3-amine (E1) was mixed in 300 mLof dimethylformamide at 0° C., and 8.2 g (48 mmol) of N-bromosuccinimidewas added to the mixture. The temperature of the reaction mixture wasreturned to the room temperature, and the mixture was stirred for eighthours. The mixture was poured into water, and the precipitate wasfiltered and then recrystallized with ethanol. After the crystals werefiltered, the crystals were washed with heptane, and then dried. As aresult, 29 g of a brown solid E2 was obtained (yield: 60%).Subsequently, 10 g (34 mmol) of E2 was charged in a 500-mL round-bottomflask, and the atmosphere in the flask was replaced with argon. Next,150 mL of methoxycyclopentane was added thereto under the argonatmosphere, and the solution was cooled to −75° C. Next, 64 mL of a 1.6Mn-butyllithium solution was added dropwise to the solution. After thedropwise addition, the temperature of the solution was returned to roomtemperature, and the solution was stirred for one hour. Subsequently,the solution was again cooled to −75° C., and 15 g of finely crushed dryice was added thereto. The temperature of the solution was graduallyreturned to room temperature. After the temperature was returned to roomtemperature, the solution was stirred for eight hours. Subsequently, 1Mhydrochloric acid was added to terminate the reaction. Next, extractionwas conducted with ethyl acetate, and the organic layer was concentratedto obtain a brownish-red liquid. The liquid was purified by columnchromatography (ethyl acetate/heptane=1:3), and recrystallization wasthen conducted with chloroform/methanol. As a result, 2.5 g (yield: 28%)of E3 was obtained in the form of yellow green crystals.

Into 200 mL of ethanol, 13.1 g (50 mmol) of E4 and 10.5 g (50 mmol) ofE5 were charged, and the solution was heated to 60° C. Subsequently, 20mL of a 5M aqueous potassium hydroxide solution was added dropwise tothe solution. After the dropwise addition, the reaction mixture washeated to 80° C., stirred for two hours, and then cooled. Subsequently,the precipitate was filtered, washed with water and ethanol, and thendried by heating at 80° C. under a reduced pressure. As a result, 20 g(yield: 92%) of dark green solid E6 was obtained.

Next, 2.3 g (5 mmol) of E6 and 1.57 g (6 mmol) of E3 were charged in 50mL of toluene, and the solution was heated to 80° C. Subsequently, 0.82g (7 mmol) of isoamyl nitrite was gradually added dropwise to thesolution, and the reaction mixture was then stirred at 110° C. for threehours. After cooling, the mixture was washed twice with 100 mL of watereach time. The organic layer was washed with saturated saline and driedover magnesium sulfate. The solution was filtered, and the filtrate wasthen concentrated to obtain a brownish-red liquid. The liquid waspurified by column chromatography (toluene/heptane=1:1), andrecrystallization was conducted with chloroform/methanol. As a result,2.58 g (yield: 85%) of E7, which was a mixture of isomers, was obtainedin the form of yellow crystals.

Into a 100-mL round-bottom flask, 1.21 g (2 mmol) of E7, 330 mg (2.2mmol) of 2,6-dimethylphenylboronic acid (E8), 0.05 g of Pd(PPh₃)₄, 20 mLof toluene, 10 mL of ethanol, and 20 mL of a 2M aqueous sodium carbonatesolution were charged, and the mixture was stirred under nitrogen at 80°C. for eight hours. After the completion of the reaction, the resultingcrystals were separated by filtration, and dispersed and washed inwater, ethanol, and heptane. The crystals were dissolved in tolueneunder heating, and the solution was subjected to hot filtration.Recrystallization was conducted with toluene/ethanol. The crystals weredried in a vacuum at 120° C., and purified by sublimation. As a result,950 mg (yield: 75%) of a mixture of Exemplary Compounds A20 and A21 wasobtained in the form of pale yellow crystals. A part of the mixture wasfurther fractionated into A20 and A21 by recrystallization.

The structure of the compound of this 1:1 mixture was confirmed by NMRspectroscopy.

¹H NMR (CDCl₃, 500 MHz) σ (ppm): 8.20 (s, 2H), 7.88-7.87 (m, 4H),7.83-7.65 (m, 22H), 7.39-7.05 (m, 20H), 6.60 (d, 1H, J=7.25 Hz), 6.52(d, 1H, J=3.6 Hz), 6.37 (d, 1H, J=7.25 Hz), 6.28 (t, 1H, J=5.10 Hz),1.89 (s, 13H).

The emission spectra of toluene solutions of Exemplary Compounds A20 andA21 with a concentration of 1×10⁻⁵ mol/L were measured using afluorescence spectrophotometer F-4500 manufactured by Hitachi, Ltd.According to the results of photoluminescence measured at an excitationwavelength of 350 nm, each of the spectra had the maximum intensity at447 nm.

Example 2 Synthesis of Exemplary Compounds A65 and A66

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E9.

The structure of the compound of a 1:1 mixture was confirmed by NMRspectroscopy.

¹H NMR (CDCl₃, 500 MHz) σ (ppm): 8.22 (d, 2H, J=6.2 Hz), 7.89-7.65 (m,30H), 7.53 (d, 2H, J=8.8 Hz), 7.49-7.47 (m, 4H), 7.42-7.30 (m, 12H),7.20-7.14 (m, 2H), 6.66 (d, 1H, J=7.25 Hz), 6.53 (d, 1H, J=7.25 Hz),6.43 (d, 1H, J=7.3 Hz), 6.30 (d, 1H, J=7.0 Hz), 1.39 (s, 18H), 1.13 (s,18H).

The emission spectrum of a toluene solution of the mixture of ExemplaryCompounds A65 and A66 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 451 nm.

Example 3 Synthesis of Exemplary Compounds A96 and A97

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E5 used in Example 1 was changed to E10 andorganic compound E8 used in Example 1 was changed to E11.

The structure of the compound of a 1:1 mixture was confirmed by NMRspectroscopy.

¹H NMR (CDCl₃, 500 MHz) σ (ppm): 8.35 (s, 1H), 8.32 (s, 1H), 7.88-7.81(m, 6H), 7.75 (s, 2H), 7.70 (s, 2H), 7.55 (s, 4H), 7.52-7.51 (m, 4H),7.39-7.16 (m, 13H), 7.07-7.02 (m, 2H), 6.96 (s, 3H), 6.62 (d, 1H, J=7.2Hz), 6.52 (d, 1H, J=6.5 Hz), 6.38 (d, 1H, J=7.0 Hz), 6.32 (d, 1H, J=7.0Hz), 2.36 (s, 6H), 1.87 (s, 12H), 1.44 (t, 36H, J=3.35 Hz), 1.40 (s,36H).

The emission spectrum of a toluene solution of the mixture of ExemplaryCompounds A96 and A97 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 449 nm.

Example 4 Synthesis of Exemplary Compounds A85 and A89

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E12.

The structure of the compound of a 1:1 mixture was confirmed by NMRspectroscopy.

¹H NMR (CDCl₃, 500 MHz) σ (ppm): 8.22 (d, 2H, J=6.45 Hz), 7.99-7.97 (m,4H), 7.92 (s, 2H), 7.88 (d, 4H, J=7.25 Hz), 7.84-7.67 (m, 20H),7.42-7.24 (m, 24H), 7.18-7.14 (m, 8H), 7.05 (d, 1H, J=7.0 Hz), 6.66 (d,1H, J=7.15 Hz), 6.52 (d, 1H, J=6.5 Hz), 6.43 (d, 1H, J=7.5 Hz), 6.29 (d,1H, J=6.6 Hz), 2.83 (s, 6H), 2.24 (s, 6H).

The emission spectrum of a toluene solution of the mixture of ExemplaryCompounds A85 and A89 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 451 nm.

Example 5 Synthesis of Exemplary Compounds A26 and A27

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E11.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A26 and A27 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 445 nm.

Example 6 Synthesis of Exemplary Compounds A93 and A95

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E5 used in Example 1 was changed to E13.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A93 and A95 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 449 nm.

Examples 7 to 30

In Examples 7 to 30, the multilayer organic light-emitting devicesdescribed in the fifth example (anode/hole injectionlayer/hole-transporting layer/light-emitting layer/hole•exciton-blockinglayer/electron-transporting layer/cathode) were prepared. In eachexample, first, an ITO film having a thickness of 100 nm was patternedon a glass substrate. On the substrate having the ITO film thereon,organic layers and electrode layers described below were successivelydeposited by a resistance-heating vacuum evaporation method in a vacuumchamber at a pressure of 10⁻⁵ Pa so that the area of the electrodesfacing each other was 3 mm². When a guest material includes two types ofcompounds, the guest material is a mixture of structural isomers havingsubstituents at different positions, the mixture having a ratio of about1:1.

Hole injection layer/Hole-transporting layer (30 nm): G-1 Light-emittinglayer (30 nm); Host: G-2, Guest: Exemplary Compound (weight ratio: 5%)

Hole/exciton-blocking layer (10 nm): G-3

Electron-transporting layer (30 nm): G-4

Metal electrode layer 1 (1 nm): LiF

Metal electrode layer 2 (100 nm): Al

The current-voltage characteristic of each EL device was measured with apA meter 4140B manufactured by Hewlett-Packard Development Company, andthe light-emission luminance thereof was measured with a luminance meterBM7 manufactured by Topcon Corporation. The luminous efficiency and thevoltage of Example 7 to Example 30 are shown in Table 4.

TABLE 4 Luminous efficiency Voltage Guest G-2 (cd/A) (V) Example 7 A1H12 6.5 4.2 Example 8 A1, A2 H12 6.5 4.2 Example 9 A4 H4  6.1 4.0Example 10 A20 H21 6.4 4.2 Example 11 A20, A21 H21 6.4 4.2 Example 12A20, A21 H10 5.8 4.0 Example 13 A21 H21 6.4 4.2 Example 14 A26, A27 H226.0 4.6 Example 15 A35, A36 H9  5.8 5.0 Example 16 A37 H15 5.8 4.7Example 17 A44 H23 6.6 4.1 Example 18 A44, A45 H27 5.6 5.0 Example 19A48, A50 H8  5.5 4.8 Example 20 A51, A52 H10 5.5 4.7 Example 21 A65, A66H22 6.5 4.5 Example 22 A67, A68 H27 6.0 4.3 Example 23 A85, A89 H28 5.65.1 Example 24 A96, A97 H9  5.4 5.3 Example 25 A113, A114 H10 5.8 4.7Example 26 A118 H2  3.9 5.9 Example 27 B4 H23 6.4 4.3 Example 28 B25 H286.3 4.0 Example 29 C5, C8 H23 4.3 5.5 Example 30 C10 H18 4.8 6.1

Examples 31 to 35

In Examples 31 to 35, the multilayer organic light-emitting devicesdescribed in the fifth example (anode/hole injectionlayer/hole-transporting layer/light-emitting layer/electron-transportinglayer/electron injection layer/cathode) were prepared. Organiclight-emitting devices having a resonating structure were prepared by amethod described below. In each example, first, an aluminum alloy (AlNd)functioning as a reflective anode was deposited on a glass substratefunctioning as a support by a sputtering method so as to have athickness of 100 nm. Furthermore, ITO functioning as a transparent anodewas deposited by a sputtering method so as to have a thickness of 80 nm.Next, an element isolation film composed of an acrylic resin and havinga thickness of 1.5 μm was formed in a peripheral portion of the anode,and an opening with a radius of 3 mm was formed therein. The substratewas sequentially washed with ultrasonic waves using acetone andisopropyl alcohol (IPA). The substrate was then washed with IPA underboiling, and dried. Furthermore, UV/ozone cleaning was conducted on thesurface of the substrate. Furthermore, organic layers described belowwere successively deposited by a resistance-heating vacuum evaporationmethod in a vacuum chamber at a pressure of 10⁻⁵ Pa. Subsequently, IZOwas deposited as a cathode by a sputtering method to form a transparentelectrode having a thickness of 30 nm. After the formation, sealing isperformed in a nitrogen atmosphere. Thus, the organic light-emittingdevices were prepared.

Hole injection layer (95 nm): G-11

Hole-transporting layer (10 nm): G-12

Light-emitting layer (35 nm); Host: G-13, Guest: Exemplary Compound(weight ratio: 2%)

Electron-transporting layer (10 nm): G-14

Electron injection layer (70 nm): G-15 (weight ratio: 80%), Li (weightratio: 20%)

The current-voltage characteristic of each EL device was measured with apA meter 4140B manufactured by Hewlett-Packard Development Company, andthe light-emission luminance thereof was measured with a luminance meterBM7 manufactured by Topcon Corporation. The luminous efficiency and thevoltage of Example 31 to Example 35 are shown in Table 5.

TABLE 5 Luminous efficiency Voltage Guest G-13 (cd/A) (V) Example 31A20, A21 H7  3.0 4.1 Example 32 A38, A39 H22 3.1 4.5 Example 33 A48, A50H8  3.4 4.3 Example 34 A51, A52 H10 3.4 4.6 Example 35 A93, A95 H8  3.14.0

Example 36 Synthesis of Exemplary Compounds A44 and A45

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E14.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A44 and A45 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 450 nm.

Example 37 Synthesis of Exemplary Compounds A147 and A148

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E15.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A147 and A148 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 451 nm.

Example 38 Synthesis of Exemplary Compounds A35 and A36

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E16.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A35 and A36 with a concentration of 1×10⁻⁵ mol/L was measuredusing a fluorescence spectrophotometer F-4500 manufactured by Hitachi,Ltd. According to the result of photoluminescence measured at anexcitation wavelength of 350 nm, the spectrum had the maximum intensityat 451 nm.

Example 39 Synthesis of Exemplary Compounds A149 and A150

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E17.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A149 and A150 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 448 nm.

Example 40 Synthesis of Exemplary Compounds A155 and A156

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E18.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A155 and A156 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 447 nm.

Example 41 Synthesis of Exemplary Compounds A151 and A152

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E19.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A151 and A152 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 446 nm.

Example 42 Synthesis of Exemplary Compounds A163 and A164

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E8 used in Example 1 was changed to E20.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A163 and A164 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 446 nm.

Example 43 Synthesis of Exemplary Compounds A157 and A158

The reactions and purifications were conducted as in Example 1 exceptthat organic compound E5 used in Example 1 was changed to E10 andorganic compound E8 used in Example 1 was changed to E17.

The emission spectrum of a toluene solution of a mixture of ExemplaryCompounds A157 and A158 with a concentration of 1×10⁻⁵ mol/L wasmeasured using a fluorescence spectrophotometer F-4500 manufactured byHitachi, Ltd. According to the result of photoluminescence measured atan excitation wavelength of 350 nm, the spectrum had the maximumintensity at 447 nm.

Examples 44 to 54

In Examples 44 to 54, the multilayer organic light-emitting devicesdescribed in the fifth example (anode/hole injectionlayer/hole-transporting layer/light-emitting layer/hole•exciton-blockinglayer/electron-transporting layer/cathode) were prepared. In eachexample, first, an ITO film having a thickness of 100 nm was patternedon a glass substrate. On the substrate having the ITO film thereon,organic layers and electrode layers described below were successivelydeposited by a resistance-heating vacuum evaporation method in a vacuumchamber at a pressure of 10⁻⁵ Pa so that the area of the electrodesfacing each other was 3 mm². When a guest material includes two types ofcompounds, the guest material is a mixture of structural isomers havingsubstituents at different positions, the mixture having a ratio of about1:1.

Hole injection layer (20 nm): G-16

Hole-transporting layer (10 nm): G-17

Light-emitting layer (30 nm); Host: G-18, Guest: Exemplary Compound(weight ratio: 5%)

Hole/exciton-blocking layer (10 nm): G-19

Electron-transporting layer (30 nm): G-20

Metal electrode layer 1 (1 nm): LiF

Metal electrode layer 2 (100 nm): Al

The current-voltage characteristic of each EL device was measured with apA meter 4140B manufactured by Hewlett-Packard Development Company, andthe light-emission luminance thereof was measured with a luminance meterBM7 manufactured by Topcon Corporation. The luminous efficiency and thevoltage of Example 44 to Example 54 are shown in Table 6.

TABLE 6 Luminous efficiency Voltage Guest G-18 (cd/A) (V) Example 44A20, A21 H31 6.1 4.2 Example 45 A35, A36 H30 6.2 4.1 Example 46 A44, A45H10 5.8 4.0 Example 47 A44, A45 H21 6.4 4.2 Example 48 A147, A148 H296.3 4.2 Example 49 A149, A150 H31 6.5 4.1 Example 50 A155, A156 H21 6.44.2 Example 51 A151, A152 H31 6.0 4.3 Example 52 A157, A158 H8  5.1 4.0Example 53 A163, A164 H21 6.1 4.0 Example 54 A163, A164 H31 6.3 4.2

RESULTS AND DISCUSSION

The organic compounds according to the present invention are novelcompounds which exhibit a high quantum yield and which are suitable forblue-light emission. When the organic compounds according to the presentinvention are used in organic light-emitting devices, it is possible tomake light-emitting devices having good luminescence properties.

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all such modifications and equivalent structures andfunctions.

This application claims the benefit of Japanese Patent Application No.2009-105356, filed Apr. 23, 2009 and No. 2010-015851 filed Jan. 27,2010, which are hereby incorporated by reference herein in theirentirety.

The invention claimed is:
 1. An acenaphtho[1,2-k]benzo[e]acephenanthrenederivative represented by general formula (1):

wherein R₁ to R₈ and R₁₀ to R₁₅ are each independently selected from ahydrogen atom, a halogen atom, a substituted or unsubstituted alkylgroup, a substituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group; wherein R₉ andR₁₆ are each a substituted or unsubstituted aryl group; wherein at leastone of R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group, and wherein at least one of R₅, R₆, R₁₂ and R₁₃ is asubstituted or unsubstituted aryl group.
 2. An organic light-emittingdevice comprising: a cathode; an anode; and an organic compound layerdisposed between the anode and the cathode, wherein the organic compoundlayer contains an acenaphtho[1,2-k]benzo[e]acephenanthrene derivativerepresented by general formula (1):

wherein R₁ to R₁₆ are each independently selected from a hydrogen atom,a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group; and at least oneof R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group, wherein the organic compound layer is alight-emitting layer, and wherein the light-emitting layer includes ahost material and a guest material, and theacenaphtho[1,2-k]benzo[e]acephenanthrene derivative is the guestmaterial.
 3. An image display apparatus comprising: a plurality ofpixels, each of which is the organic light-emitting device according toclaim 2; and a unit configured to supply an electrical signal to theorganic light-emitting device.
 4. An apparatus comprising: a substrate;the organic light-emitting device according to claim 2; and a colorfilter film.
 5. An electrophotographic image-forming apparatuscomprising: a photosensitive drum; the organic light-emitting deviceaccording to claim 2 configured to form a latent image on thephotosensitive drum.
 6. An illuminating apparatus comprising: aplurality of organic light-emitting devices according to claim 2,wherein the plurality of organic light-emitting devices is arranged inan in-plane direction.
 7. An apparatus comprising: a substrate; anorganic light-emitting device; and a color filter film, wherein theorganic light-emitting device comprises: a cathode; an anode; and anorganic compound layer disposed between the anode and the cathode,wherein the organic compound layer contains anacenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented bygeneral formula (1):

wherein R₁ to R₁₆ are each independently selected from a hydrogen atom,a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group; and at least oneof R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group.
 8. An electrophotographic image-forming apparatuscomprising: a photosensitive drum; and an organic light-emitting deviceconfigured to form a latent image on the photosensitive drum, whereinthe organic light-emitting device comprises: a cathode; an anode; and anorganic compound layer disposed between the anode and the cathode,wherein the organic compound layer contains anacenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented bygeneral formula (1):

wherein R₁ to R₁₆ are each independently selected from a hydrogen atom,a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group; and at least oneof R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group.
 9. An illuminating apparatus comprising: a pluralityof organic light-emitting devices, wherein the plurality of organiclight-emitting devices is arranged in an in-plane direction, and whereinthe plurality of organic light-emitting devices comprise: a cathode; ananode; and an organic compound layer disposed between the anode and thecathode, wherein the organic compound layer contains theacenaphtho[1,2-k]benzo[e]acephenanthrene derivative represented bygeneral formula (1):

wherein R₁ to R₁₆ are each independently selected from a hydrogen atom,a halogen atom, a substituted or unsubstituted alkyl group, asubstituted or unsubstituted alkoxy group, a substituted orunsubstituted amino group, a substituted or unsubstituted aryl group,and a substituted or unsubstituted heterocyclic group; and at least oneof R₁ to R₈ and R₁₀ to R₁₅ is selected from a halogen atom, asubstituted or unsubstituted alkyl group, a substituted or unsubstitutedalkoxy group, a substituted or unsubstituted amino group, a substitutedor unsubstituted aryl group, and a substituted or unsubstitutedheterocyclic group.